1. Field of Invention
This invention relates to chimney dampers. More particularly, this invention relates to an improved chimney damper containing a means for opening the chimney damper even when it is stuck closed.
2. Prior Art
In homes and other buildings having a fireplace, the fireplace opening is connected to a chimney flue which is open to the outside of the building. When in use, the combustion products from the fireplace pass up through the flue and exit the chimney in a conventional fashion.
When the fireplace is not in use, however, the fireplace opening and chimney flue form a passage through which heat can escape from the interior of the building. Although most fireplaces contain conventional fireplace dampers at the bottom of the flue or immediately above the fireplace opening, these fireplace dampers do not usually provide an adequate seal for the chimney flue. This inadequate seal permits a great deal of heat loss through the chimney flue.
A number of chimney dampers have been produced which are mounted on the top of the chimney to provide a better seal and thus reduce the amount of heat lost through the chimney flue. Various types of chimney dampers are available. For example, one well known type of chimney damper is a cap-type flue damper as shown in U.S. Pat. Nos. 4,554,863, 4,181,119 and 4,020,754.
Another common type of chimney damper has a lid attached to the side of the chimney by hinges as shown in U.S. Pat. Nos. 4,691,624, 4,528,897, 4,483,315, 4,368,663 and 2,856,839.
Another common type of chimney damper contains a frame secured to the top of the chimney and a flap which is pivotally attached to the frame to provide an improved method of both closing the flue and also preventing air and water from flowing over the damper flap into the chimney. See, for example, U.S. Pat. No. 2,704,502 and the particularly preferred inventions shown in U.S. Pat. Nos. 3,945,307 and 4,165,679.
A disadvantage of many of the previously known dampers is that the exposed surface of the damper contains areas in which water may collect. This water, upon freezing, can lock the damper in a closed position creating a safety hazard for operation of the fireplace. One method of solving this problem was proposed in U.S. Pat. No. 3,945,307 which discloses a cup (15) which is attached to a spring (13) secured to the bottom of a damper flap (7) such that when the spring is stretched and then released, the cup moves abruptly upward to strike the underside of the damper flap. This striking of the damper flap is designed to free a stuck damper flap. While this method of freeing a stuck damper flap works in some situations, improved methods of releasing a stuck damper flap are still needed to assure that the damper flap never remains in a closed position as a result of the accumulation of ice, creosote or other material build up.
Accordingly, it is an object of this invention to provide a chimney damper containing a device which frees a stuck damper flap.
It is another object of this invention to provide a chimney damper which operates under many different weather conditions.
It is a still further object of this invention to provide a chimney damper which is easy to install and inexpensive to produce.
These and other objects are provided by the improved chimney damper of the instant invention.